A display panel is typically formed by cell-assembling an array substrate and a color filter substrate. Metal electrodes/wires disposed on the array substrate generate lateral electrical fields after being applied power, and such electrical fields will cause liquid crystal molecules disposed adjacent to the metal electrodes/wires to defect disorderedly, and in turn, a phenomenon of light leakage will occur in the display panel. In order to prevent light leakage in the display panel due to the lateral electrical fields generated by the metal electrodes/wires, a black matrix is typically disposed on the color filter substrate, so as to prevent light leakage due to the lateral electrical fields generated by the metal electrodes/wires and to avoid influence on leakage current in a channel region of a TFT (TFT) by external light irradiation.
As a certain offset will occur when cell-assembling the color filter substrate and the array substrate, size of the black matrix is designed to be greater than necessary, which cause the opening ratio of the display panel to decrease.